Hesitation between 4 and 6 grand under boost

[slaminGSX]

Wondering if ya guys had any advice for me on the problem that I am having. Couple months back i blew the original engine in my 91 eclipse GSX, so instead of doing a basic rebuild i decided to up grade a little. I will list my mods on the end of the post. The problem that I have been having is that my car now hesitates between 4 and 6 grand under boost. I have a MAFT in blow through set-up and a SAFC II. If I try and do a third gear pull on the highway, my turbo spools around 4 grand, as soon as the turbo is spooled the car bucks and pops a little almost like it has a miss fire or is running lean. So i adjusted my SAFC, richened it up and it still did the same, leaned it out and still had the same results. But the problem only happens between 4 and 6 grand, from 6 grand on it pulls really hard. I lowered boost down to 10lbs and the problem still happens. I set the MAFT for 820 injectors and left the SAFC at 0 across the board. Under boost my timming goes to 20 degrees and gradually increases with RPM, but i m experiencing 8-10 counts of knock. Fuel pressure is set at 46lbs. Any advice on this will be greatly appreciated. Is there any other info that i should list that would help?

4g63: Ross pistons 8.5 to 1, eagle rods, ARP hardware, o-ringed block, MLS head gasket, ported head, 1mm oversized valves, 272 HKS cams, crower springs and retainers, 99 lifters, 850 FIC injectors, charged air FPR, BR580 turbo, sparco front mount, MAFT 1.3 version, SAFC II, apex N1 down pipe and catback, manual boost controller. That should be it for engine wise. AMS did the engine work.

 

[Krazeeejatt]

i would've thought so too.... that it's running lean........ jus to make sure do you have an air fuel guage???

 

[CanadianTSi]

Check your Base timing, lower your Fuel Pressure to 37 and either your Plugs/Wires are bad or your plugs need to be gapped abit smaller

Also check for boost leaks.

 

[slaminGSX]

I do have an air/fuel guage and i can watch my o2 voltage off of my logger too. My o2 voltage is in the .90 - .93 range, it is rich enough to blow black smoke out of the exhaust and leave a smoke screen.

My plugs are gapped at .28ths and i have Taylor 8 mm plug wires, my plugs are NGK 7es. My plugs have a nice tan look to em, so i m wondering if it is spark related and not fuel. I have already lowered my fuel pressure and have had the same effect. My base timming is set at 7 degress. I have also pressured my intake and have found no leaks up till 20 psi.

thanks for the replies guys.